Sulfated polysaccharides are compounds having a great importance in cosmetic, textile, alimentary and pharmaceutical industry. More particularly their use is recommended in prevention of venous thrombosis (I. B. Jacques, Pharmacological Reviews, 1979, 31, 99-166).
Besides, low molecular weight sulfated polysaccharides have been proposed as antithrombotic non-anticoagulant agents, thus involving a weak hemorragic risk (D. P. Thomas, Seminars in Hematology, 1978, 15, 1-17).
Chitosan is a polysaccharide consisting of 400 to 6000 beta-D(1,4)-glucosamine subunits containing from zero to 30% of acetyl groups attached to the amino group of glucosamine.
Methods for the sulfation of chitosan are described in the literature.
Such methods afford chitosan sulfates having the sulfate groups randomly fixed to one of the hydroxy groups in the 3 and 6 positions and to the amino groups in the 2 position of the glucosamine unit.